56th  Congress,  /  HOUSE  OF  REPRESENTATIVES.  \  Document 
1st  Session.     \  (  No.  495. 


EXAMINATION  AND  SURVEY  OF  DIAMOND  .REEF  AND 
COENT1ES  REEF,  EAST  RIVER,  NEW  YORK. 


LETTER 

FROM 

THE  ACTING  SECRETARY  OF  WAR, 

TRANSMITTING, 

WITH  A  LETTER  FROM  THE  CHIEF  OF  ENGINEERS,  REPORTS  OF 
EXAMINATION  AND  SURVEY  OF  DIAMOND  REEF  AND  COENTIES 
REEF,  EAST  RIVER,  NEW  YORK. 


March  8,  1900. — Referred  to  the  Committee  on  Kivers  and  Harbors  and  ordered  to 

be  printed. 

* 

War  Department, 
Washington,  March  7,  1900. 
Sir:  I  have  the  honor  to  transmit  herewith  a  letter  from  the  Chief 
of  Engineers,  United  States  Army,  dated  March  6  instant,  together 
with  copy  of  a  report  from  Maj.  H.  M.  Adams,  Corps  of  Engineeis, 
dated  April  22,  1899,  and  copy  of  report  from  Maj.  W.  L.  Marshall, 
Corps  of  Engineers,  dated  February  28, 1900,  the  former  of  a  prelimi- 
nary examination  and  the  latter  of  a  survey  of  Diamond  Reef  and 
Coenties  Reef,  in  East  River.  New  York,  made  by  them  in  compliance 
with  the  provisions  of  the  river  and  harbor  act  of  March  3,  1899. 
Very  respectfully, 

G.  D.  Meiklejohn, 

Acting  Secretary  of  War. 
The  Speaker  of  the  House  of  Representatives. 


Office  of  the  Chief  of  Engineers, 

United  States  A  rot, 
Washington,  March  6,  1900. 
Sir:  The  river  and  harbor  act  of  March  3,  1899.  provided  for  a 
•reliminarv  examination  and  survey  of  Diamond  Reef  and  Coenties 
fceef,  in  East  River,  New  York,  with  a  view  to  their  removal,  and  I 
H.  Doc.  91  44 


2      DIAMOND  REEF  AND  COENTIES  REEF,  EAST  RIVER,  N.  Y. 

now  have  the  honor  to  submit  the  accompanying  copy  of  report  dated 
April  22,  1899,  by  Maj.  H.  M.  Adams,  Corps  of  Engineers,  upon 
preliminary  examination,  and  copy  of  report  dated  February-  28, 1900, 
with  map,  by  Maj.  W.  L.  Marshall,  Corps  of  Engineers,  upon  survey 
of  the  locality. 

The  plan  of  improvement  proposed  by  Major  Marshall  provides  for 
removing  these  reefs,  including  that  part  of  Diamond  Reef  known  as 
reef  off  Diamond  Reef,  to  a  clear  depth  of  at  least  32  feet  at  mean 
low  water  (excavation  estimated  to  a  depth  of  34  feet),  at  an  estimated 
cost,  including  contingencies,  of  $1,897,500. 

In  the  opinion  of  the  local  officer,  improvement  to  the  extent  indi- 
cated is  worthy  of  being  undertaken  by  the  General  Government,  and 
his  views  are  concurred  in  by  Col.  G.  L.  Gillespie,  Corps  of  Engineers, 
the  division  engineer. 

Very  respectfully,  your  obedient  servant, 

John  M.  Wilson, 
Brig.  Gen.,  Chief  of  Engineers, 

U.  S.  Army. 

Hon.  Elihu  Root, 

Secretary  of  War. 


PRELIMINARY  EXAMINATION  OF  DIAMOND  REEF  AND  COENTIES  REEF, 
EAST  RIVER,  NEW  YORK,  WITH  A  VIEW  TO  THEIR  REMOVAL. 

United  States  Engineer  Office, 

New  York  City,  April  22,  1899. 

General  :  I  have  the  honor  to  submit  the  following  report  upon  a 
preliminary  examination  of  Diamond  Reef  and  Coenties  Reef,  in  East 
River,  with  a  view  to  their  removal,  made  under  authority  of  the  river 
and  harbor  act  of  1899. 

These  reefs  lie  at  the  south  end  of  East  River,  at  and  near  its  junc- 
tion with  Buttermilk  Channel  and  the  channel  between  the  Battery  and 
Governors  Island.  New  York  Harbor. 

Diamond  Reef  covers  an  area,  at  the  curve  of  30  feet  depth,  about 
800  feet  long,  with  600  feet  greatest  width.  Coenties  Reef,  a  quarter 
of  a  mile  farther  up  East  River,  is  about  280  feet  long  and  150  feet 
wide,  Originally  these  reefs  had  least  depths  of  17.5  feet  and  11.3  feet, 
respectively.  In  1875  Coenties  Reef  was  removed  to  a  depth  of  scant 
26  feet  (about  25£  feet  clear  depth),  and  in  1892  the  removal  of  Diamond 
Reef  to  26  feet  depth  was  completed. 

Between  East  River  and  North  River  there  is  a  natural  channel  of 
about  35  feet  depth,  having  a  general  width  of  1,200  feet  except  for  a 
length  of  1,000  feet,  where  Diamond  Reef,  lying  in  the  south  side  of 
this  channel,  reduces  the  width  to  about  200  feet.  Coenties  Reef  lies 
almost  directly  in  the  axis  of  this  narrow  channel,  where  the  harbor  is  \ 
most  crowded  by  vessels  and  where  the  tidal  currents  arc  very  strong. 
These  conditions  make  navigation  there  very  difficult  for  vessels  of  too 
great  draft  to  pass  over  the  reefs. 

The  river  and  harbor  act  of  1896  ordered  a  survey  of  "the  channel 
between  the  Battery  and  Governors  Island,  with  a  view  to  making  a| 
channel  continuous  with  Buttermilk  Channel  thirty  feet  in  depth  and 


DIAMOND  REEF  AND  COENTIES  REEF,  EAST  RIVER,  N.  Y.  3 

one  thousand  two  hundred  feet  in  width."  In  connection  with  this 
survey  some  borings  were  made  to  ascertain  the  area  of  Diamond 
Reef  at  this  depth.  The  report,  printed  in  the  Annual  Report  of  the 
Chief  of  Engineers  for  1897,  page  1182,  contained  estimates  of  cost 
of  removing  Diamond  Reef  and  Coenties  Reef  to  32  feet  depth.  It 
also  contained  the  following  statements  relating  to  the  commerce  of 
the  vicinity: 

There  are  no  data  showing  the  amount  or  value  of  the  commerce  which  passes 
through  the  channel  between  the  Battery  and  Governors  Island.  At  different  times 
during  January,  1897,  for  four  and  one-third  hours  altogether,  the  numbers  and  kinds 
of  vessels  passing  this  channel  have  been  observed,  with  the  following  as  the  average 
result  per  hour: 


Kind  of  boats. 


Number 
per  hour. 


Ferryboats  

Towboats  without  tows,  and  small  steamers 

Towboats  with  tows  

Barges,  etc.,  in  tow  

Ships,  barks,  and  brigs,  in  tow  

Steam  lighters  

Large  steamers  

Car  floats  

Railroad  ferries  

Total  


125 


Excluding  the  ferryboats,  the  total  per  hour  is  93,  of  which  87  pass  in  midchannel 
or  nearer  the  Battery  shore. 

As  nearly  as  can  be  estimated  the  observed  traffic  would  be  a  fair  average  for  ten 
hours  of  the  day  and  nearly  three  times  too  great  for  the  other  fourteen  hours,  which 
would  make  the  total  traffic  per  day  fifteen  times  that  observed  per  hour. 

Similar  observations  made  in  summer  would  show  a  greater  number  of  vessels;  at 
that  season  there  are  from  50  to  100  excursion  steamers  daily  passing  the  Battery, 
together  with  many  pleasure  boats,  and  large  fleets  of  canal  boats  and  barges  from 
the  Erie  Canal  and  Upper  Hudson,  whose  navigation  is  now  [February,  1897]  shut 
off  by  ice. 

Nearly  all  of  the  above  vessels  pass  close  to  or  immediately  over 
Diamond  and  Coenties  reefs.  All  but  the  largest  boats  pass  over  the 
reefs  freely,  but  the  fact  that  the  boats  of  deep  draft  must  of  necessity 
follow  a  narrow  course  in  a  crowded  channel  creates  an  obstruction  to 
vessels  of  all  kinds.  Events  within  the  past  year  have  demonstrated 
the  need  of  a  deep  and  unobstructed  channel  from  the  sea  to  the  New 
York  Navy -Yard,  in  East  River,  above  these  reefs. 

The  survey  of  the  channel  between  the  Battery  and  Governors 
Island  made  in  the  winter  of  1896-97  included  borings  sufficient  to 
determine  the  approximate  contour  of  these  reefs  at  a  depth  of  32  feet 
below  mean  low  water,  and  to  make  an  estimate  of  the  probable  cost 
of  removal.  The  season  of  the  year  (winter)  was  not  favorable  for 
making  a  detailed  survey  of  the  reefs,  such  as  would  be  necessary 
before  actual  removal.  Such  a  survey  Avould  be  very  expensive,  under 
the  most  favorable  conditions,  on  account  of  the  rapid  currents,  the 
crowded  channel,  and  the  hard  material  underlying  Diamond  Reef. 
It  could  be  made  to  best  advantage  during  summer  and  fall  months. 
******* 

In  my  opinion  the  removal  of  Diamond  Reef  and  Coenties  Reef  in 
East  River,  New  York  Harbor,  to  a  depth  of  32  feet  below  mean  low 
water  is  a  work  of  public  importance,  worthy  to  be  undertaken  by 
the  United  States  in  view  of  the  great  commercial  interests  involved. 


4       DIAMOND  REEF   AND  COENTIES   REEF,  EAST  RIVER,  N.  Y. 


It  is  recommended  that  a  detailed  survey  of  these  reefs  be  author- 
ized   *    *  *. 

Very  respectfully,  your  obedient  servant, 

H.  M.  Adams, 

Major,  Corps  of  Engineers, 

Brig.  Gen.  John  M.  Wilson, 

Chief  of  Engineers,  U,  /S.  A. 

(Through  the  Division  Engineer.) 

[Third  indorsement.] 

Northeast  Division  Engineer  Office, 

New  York,  May  6,  1899. 
Respectfully  returned  to  the  Chief  of  Engineers. 
When  work  ceased  on  Diamond  Reef  and  Coenties  Reef,  the  adopted 
navigable  depth  for  this  port  was  26  feet  at  mean  low  water.  Since 
1892  the  demand  has  been  for  increased  depth  extending  to  35  feet, 
mean  low  water,  increased  to  40  feet,  mean  low  water,  over  the  bar  at 
the  southern  entrance. 

The  great  draft  of  modern  naval  vessels  and  the  obstruction  offered 
to  their  passage  up  East  River  at  low  tide,  notably  the  accident  to  the 
U.  S.  S.  Massachusetts  within  the  past  few  months,  show  the  importance 
of  increasing  the  navigable  depth  over  the  reefs  in  the  channel  leading 
from  the  navy-}7ard  to  the  lower  bay  to  35  feet  at  mean  low  water.  I 
therefore  concur  in  the  recommendation  of  *he  district  officer  that  the 
said  reefs  be  lowered  to  the  plane  of  32  feet  at  mean  low  water,  and 
that  a  survey  to  this  end     *    *    *    be  authorized. 

G.  L.  Gillespie, 
Colonel,  Corps  of  Engineers, 

Division  Engineer. 

[Sixth  indorsement.] 

Office  Chief  of  Engineers, 

U.  S.  Army, 
August  H,  1899. 

Respectfully  submitted  to  the  Secretary  of  War. 

In  accordance  with  the  provisions  of  the  river  and  harbor  act  of  March 
3,  1899,  a  preliminary  examination  has  been  made  of  Diamond  Reef 
and  Coenties  Reef,  in  East  River,  New  York,  with  a  view  to  their 
removal. 

The  localit}T  is  reported  to  be  worthy  of  improvement,  and  I  recom- 
mend that  a  survey  be  made  and  the  cost  of  improvement  be  estimated. 

A.  Mackenzie, 

Acting  Chief  of  Engineers. 

War  Department, 

August  15,  1899. 
Approved  as  recommended  by  the  Acting  Chief  of  Engineers. 
By  order  of  the  Secretary  of  War; 

John  C.  Scofield, 

Chief  Clark 


DIAMOND  REEF  AND  COENTIES  REEF,  EAST  RIVER,  N.  Y.  5 


SURVEY  OF  DIAMOND  REEF  AND  COENTIES  REEF.  EAST  RIVER,  NEW 
YORK,  WITH  A  VIEW  TO  THEIR  REMOVAL. 

Engineer  Office,  United  States  Army, 

New  York,  N.  Y,  February  %8,  1900. 

General:  In  compliance  with  Department  letter  dated  August  18, 
1899,  I  have  the  honor  to  submit  the  following;  report,  with  estimates 
upon  the  survey  of  Diamond  Reef  and  Coenties  Reef,  in  East  River, 
New  York,  made  to  comply  with  the  terms  of  the  river  and  harbor 
act  approved  March  3,  1899: 

The  results  of  the  survey  and  locations  of  the  reefs  are  exhibited  on 
the  accompanying  map. 

The  original  condition  of  these  reefs  and  the  reasons  for  their  removal 
are  fully  stated  in  the  report  upon  preliminary  examination  dated 
April  22,  -1899,  and  in  the  report  upon  survey  of  channel  between  the 
Battery  and  Governors  Island,  printed  as  House  Doc.  No.  331:,  Fifty- 
fourth  Congress,  second  session,  and  in  Annual  Report  of  the  Chief  of 
Engineers  for  1897,  pages  1182  to  1185,  which  also  contains  commer- 
cial statistics  and  estimates  for  the  removal  of  the  reefs  to  32  feet  at 
mean  low  water. 

The  commercial  considerations  involved  in  the  removal  of  these 
reefs  to  meet  the  needs  of  navigation,  both  past  and  present,  have 
been  thoroughly  reviewed  in  the  above-mentioned  reports,  and  in  the 
Annual  Reports  of  the  Chief  of  Engineers  upon  the  improvement  of 
East  River  for  the  past  twenty  years  or  more. 

This  survey  has  been  conducted  with  a  view  of  showing  the  character 
and  amount  of  material  necessary  to  be  removed  to  make  a  clear  depth 
of  32  feet  at  rnean  low  water  over  Diamond  Reef  and  Coenties  Reef, 
which  depth  is  now  required  to  meet  the  demands  of  navigation  at  the 
mouth  of  East  River. 

The  survey  was  planned  and  executed  under  direction  of  Lieut.  Col. 
W.  H.  H.  Benyaurd,  by  a  party  in  charge  of  Mr.  H.  B.  Gorham, 
assistant  engineer.  The  held  work  was  commenced  on  September  11, 
and  completed  on  December  2,  1899.  On  account  of  the  rapid  tidal 
currents  over  and  around  the  reefs,  and  the  crowded  condition  of  the 
channel  by  vessels  of  all  classes,  the  floating  plant  required  on  the  sur- 
vey had  to  be  of  the  most  substantial  character,  and  after  due  consider- 
ation the  large  dredge  Hell  Gate  and  the  tug  General  A.  A.  Eumphn  ys, 
of  the  East  River  rock-removing  plant  owned  by  the  United  States, 
were  placed  in  commission  and  used  until  the  completion  of  the  held 
work.  The  dredge  was  run  into  several  times  without  causing  serious 
damage,  but  upon  two  occasions  the  damage  was  so  great  as  to  neces- 
sitate its  withdrawal  from  the  work  for  repairs.  The  bills  for  repairs 
in  each  of  these  cases  were  paid  by  the  owners  of  the  vessels  which 
caused  the  damage. 

The  delays  caused  by  collisions  and  a  protracted  period  of  foggy 
weather  had  the  effect  of  prolonging  the  time  of  the  survey  at  least  a 
month,  and  thereby  added  considerably  to  its  cost  *  *  *.  Experi- 
ence has  demonstrated  that  it  is  impossible  for  a  vessel  to  remain  at 
anchor  over  these  reefs  without  being  run  into,  and  there  are  times 
when  moving  vessels  are  so  numerous  that  there  is  an  entire  block  in 
the  navigation  for  a  short  period.    This  fact  makes  it  necessary  to  add 


6      DIAMOND  REEF  AND  COENTIES  REEF,  EAST  RIVER,  N.  Y. 


considerably  to  the  estimated  cost  of  removal  of  these  reefs,  particu- 
larly Coenties  Reef,  as  any  plant  placed  there  for  the  purpose  of 
working  upon  that  reef  is  liable  to  be  run  into  and  sunk  at  any  time. 
The  borings  and  soundings  were  taken  from  the  dredge,  which  was 
held  in  a  fixed  position  by  four  large  anchors  and  chains.  The  borings 
were  made  with  a  3-inch  steel  angle  or  drill,  and  with  few  exceptions 
the  holes  were  bored  through  to  rock  bottom.  The  exceptions  were  in 
cases  where  holes  were  carried  to  the  full  length  of  the  drill  and  no 
rock  was  found.  The  dredge  was  moved  into  the  required  positions 
by  hauling  in  the  chains  by  means  of  the  steam  windlasses  or  winches 
with  which  the  dredge  is  fully  equipped.  In  each  position  2  borings 
and  13  soundings  were  taken,  and  by  means  of  systematic  moves  the 
dredge  occupied  eight  positions  per  hour,  during  which  time  16  borings 
and  104  soundings  were  taken. 

It  was  found  impracticable  to  secure  accurate  results  by  the  means 
employed,  during  the  full  strength  of  the  tides,  consequently  the  work 
was  carried  on  only  during  the  period  of  slack  tides  and  minimum 
velocities  of  the  tidal  currents. 

The  borings  and  soundings  were  located  from  the  dredge  by  sextant 
angles  to  fixed  stations  upon  the  shores  of  Governors  Island,  New  York, 
and  Brooklyn.  These  shore  stations  were  located  by  triangulation 
from  the  bases  of  the  United  States  Engineer  Department  and  United 
States  Coast  Survey. 

There  is  a  covering  of  loose  material  upon  the  reefs,  particularly  on 
Diamond  Reef,  which  consists  of  gravel  and  broken  stone  left  from 
former  work.  This  loose  material  will  be  difficult  to  remove,  and  it  is 
impracticable  to  make  a  separate  estimate  for  its  removal,  as  a  quantity 
of  such  material  will  always  remain  lodged  in  the  crevices  all  over  the 
surface  of  the  blasted  reefs.  Diamond  Reef,  at  the  32-foot  curve,  at 
least,  consists  of  two  parts,  the  easterly  part  being  known  as  "reef  off 
Diamond  Reef."  The  following  estimates  provide  for  the  removal  of 
both  parts: 

Estimates. 

For  removing  Diamond  Reef  to  make  a  clear  depth  of  at  least  32  feet  at 
mean  low  water  (excavation  estimated  to  34  feet) ,  48,000  cubic  yards  of 
rock,  at  $30  per  cubic  yard  $1, 440, 000 

For  removing  Coenties  Reef  to  make  a  clear  depth  of  at  least  32  feet  at 
mean  low  water  (excavation  estimated  to  34  feet),  9,500  cubic  yards  of 
rock,  at  $30  per  cubic  yard   285, 000 

Contingencies,  supervision,  etc.,  10  per  cent   172, 500 

Total   1, 897, 500 

In  my  opinion  the  East  River,  New  York,  is  worthy  of  additional 
improvement  by  the  General  Government  on  the  plans  and  to  the 
extent  above  set  forth. 

Very  respectfully,  your  obedient  servant, 

W.  L.  Marshall, 
Major,  Cordis  of  Engineers, 

Brig.  Gen.  John  M.  Wilson, 

Chief  'of '  Engineers,  U.  S.  A. 

(Through  the  Division  Engineer.) 


DIAMOND  REEF  AND  COENTIES  REEF,  EAST  RIVER.  N.  Y.  7 

[First  indorsement.] 

Northeast  Division  Engineer  Office, 

New  York,  March  2,  1900. 
Respectfully  forwarded  to  the  Chief  of  Engineers,  concurring  in 
the  views  of  the  district  officer. 

G.  L.  Gillespie, 
Colonel,  Corps  of  Engineers, 

Division  Engineer. 


Avery  Architectural  and  Fine  Arts  Library 
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